Conventionally, it is common for various vehicles such as automobiles and transporting vehicles to be equipped with a combustion engine as a power generating source. However, in recent years, in order to achieve the ideal of a low-carbon society, vehicles that are equipped with an electric motor instead of a combustion engine as a power generating source, or vehicles that are equipped with both a combustion engine and an electric motor as a power source are becoming increasingly common. Such vehicles are equipped with rechargeable batteries (for example, secondary cells such as lithium ion cells or nickel hydrogen cells or the like) that are rechargeable and that supply power to drive the electric motor, and are so constructed that the storage cells can be charged by power supplied from an external power supply device.
For example, in an electric vehicle (EV) that uses an electric motor exclusively as a power generating source, the charging of the storage cells is performed using power that is supplied from an external power supply device. Furthermore, among hybrid vehicles (HV) in which both a combustion engine and an electric motor combine to serve as a power generating source, in those hybrid vehicles that are known as plug-in hybrid vehicles, the charging of the storage cells can be performed using power supplied from an external power supply device in the same way as in an electric vehicle.
Vehicles such as the above-described electric vehicles and hybrid vehicles and the like are used as transportation means. Because of this, they are usually so constructed that the power to be supplied to the motor is charged to a storage cell using power that is supplied from the external power supply device. In contrast to this, in Patent documents 1 through 3 (see below), technology is disclosed that makes it possible to supply power from the storage cells that are installed in the electric vehicle to the outside (for example, to a house). Specifically, in the technology disclosed in these documents, an electric vehicle that has been parked adjacent to the house is connected to a house by a cable, and power is supplied to the house from the electric vehicle via this cable.